On Wed, Jul 23, 2014 at 2:53 AM, Borislav Petkov <bp@xxxxxxxxx> wrote: > > Well, it looks like we f*cked up something after -rc5 since I'm starting > to see lockdep splats all over the place which I didn't see before. I'm > running rc6 + tip/master. > > There was one in r8169 yesterday: > > https://lkml.kernel.org/r/20140722081840.GA6462@xxxxxxx > > and now I'm seeing the following in a kvm guest. I'm adding some more > lists to CC which look like might be related, judging from the stack > traces. Hmm. I'm not seeing the reason for this. > [ 31.704282] [ INFO: possible irq lock inversion dependency detected ] > [ 31.704282] 3.16.0-rc6+ #1 Not tainted > [ 31.704282] --------------------------------------------------------- > [ 31.704282] Xorg/3484 just changed the state of lock: > [ 31.704282] (tasklist_lock){.?.+..}, at: [<ffffffff81184b19>] send_sigio+0x59/0x1b0 > [ 31.704282] but this lock took another, HARDIRQ-unsafe lock in the past: > [ 31.704282] (&(&p->alloc_lock)->rlock){+.+...} Ok, so the claim is that there's a 'p->alloc_lock' (ie "task_lock()") that is inside the tasklist_lock, which would indeed be wrong. But I'm not seeing it. The "shortest dependencies" thing seems to imply __set_task_comm(), but that only takes task_lock. Unless there is something in tip/master. Can you check that this is actually in plain -rc6? Or maybe I'm just blind. Those lockdep splats are easy to get wrong. Adding PeterZ and Ingo to the list just because they are my lockdep go-to people. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
